const container = document.getElementById('container')
const canvas = document.createElement('canvas')
canvas.width = container.clientWidth
canvas.height = container.clientHeight
const cvs_width = container.clientWidth
const cvs_height = container.clientHeight
container.appendChild(canvas)
const ctx = canvas.getContext('2d')

// 所有坦克数组，用于更新画面
const all_tank = new Map()
// 人机、玩家坦克数组，检查子弹碰撞
const players_tank = new Map()
const computer_players_tank = new Map()
// 子弹数组
const all_bullet = new Map()
// 特效数组，子弹消失后，在消失位置添加特效，存储起来，特效结束删除
const special_effects_list = new Map()
